Strange Google Bot Log Entries

I am seeing really strange log file entries - today, on one of my client's sites, Googlebot attempted to visit hundreds of non-existent pages with really odd file names that have nothing to do with his business or website.

For example:

/ohio/wrongful_death/city_list_g.php

/maine/landlord_and_tenant/l/lincolnville_landlord_and_tenant_lawyers.php

/north_carolina/dog_bites/city_list_j.php

and other strange url's that do not exist, and never have.

There are literally hundreds of these 404 entries in today's log file.

For Google to be looking for them, they must be referred from somewhere. My concern is that someone has posted all these non-existent links to my client's site - but for what reason? Does a high number of 404's affect rankings?

Has anyone else noticed anything like this? I know there are bots that will look up random url's but I've never seen Google do that.

Thanks for your thoughts.

Wanted to bump this up - still seeing tons of these queries from Google Bot for these URL's that don't exist. I am suspecting a competitor may be up to something? Any thoughts on this?

someone could be backlinking to non-existant pages

Most probably someone submitted these URLs to linklicious or other crawl/index site. These services force the spider to crawl the submitted pages. Just a guess tho.

Thanks for the replies - any guesses as to why someone would do that? Submit non-existent URL's forcing Google to see tons of 404's on a site? There are literally hundreds of these queries.